Abstract:

75245S This project will develop a ¿metal rubber¿ product ¿ a highly electrically-conductive, elastomeric, and transparent nanocomposite ¿ that maintains electrical conductivity or provides EMI shielding while under mechanical, thermal, and environmental stress. The materieal can be used as lightning strike and EMI shielding protective coatings for commercial and advanced aircraft, and in state-of-the-art flexible microelectronics and sensors. During Phase I, several nanocomposites were modeled and prepared layer-by-layer by the self-assembly of metal nanoparticles and elastomeric polymers. The relationship between sheet resistance, transmission, and mechanical properties were investigated. A bulk resistivity of 10-5 O¿cm was demonstrated (recall that the resistivity of bulk gold is 10-6 O¿cm), which is important because a smaller amount of metal would be needed for manufacturing, thereby reducing costs. The tradeoff in material properties was controlled through chemical processing based on (1) the choice and volume fraction of metal nanoparticles and (2) the choice and crosslink density of the organic polymer component. In Phase II, the properties of the material will be optimized for commerical applications, especially as high performance coatings for aircraft and microelectronics packaging. Commercial Applications and Other Benefits as described by the awardee: The new ¿metal-rubber¿ material should find application as: (1) advanced window coating materials for next-generation commercial airplanes, (2) similar coatings for military aircraft transparencies, and (3) flexible conducting electrodes and mechanical sensors in the electronics market. In addition, the technology should expand the use of nanotechnology as a practical manufacturing technique.